The containers are constituted by bags of synthetic material, having a rectangular or square shape, constituted by two sheets welded along the edges thereof.
One of the two sheets comprises, in proximity of one of the smaller sides, preferably on the longitudinal axis of the bag, a filling mouth closed by a removable cap.
In the following the terms container and bag will be used interchangeably.
The containers are filled in linear machines comprising, in addition to a bag advancement line, a sterile chamber, preferably parallelepiped but also possibly cylindrical, in which the mouth is housed in the bottom, through an opening in the lower wall of the chamber.
The sterile chamber comprises means for supporting the mouth in the chamber and returning it to the advancement line, means for spraying a liquid disinfectant in the vicinity of the mouth, means for removing the cap and retaining it in a position by the side of the mouth and replacing it on the mouth, as well as a vertical-axis batcher-dispenser for introducing the product into the bag.
After the bag has been filled, the cap is reapplied to the mouth, the mouth is released to outside the chamber, and the bag is laid on the advancement line.
All the above-described operations are carried out using devices that are in themselves known to the technical expert in the sector, and which will be omitted from the detailed description.
Known linear machines have the disadvantage of a low production capacity due to the difficulty of changing the format of the containers, mouths and removable caps, as well as being due to the time the bag remains in the filling station—the time being the time required for performing all of the above-described operations.
Approximately these operations require a total time of more than about 5 seconds per bag, while the time required only for filling the bag is in the order of a second or a little more, depending on the capacity of the bag.
The purpose of the present invention is to obviate all these problems with a simple and effective solution.
This aim is attained by a filling machine having the characteristics recited in the independent claim; the dependent claims relate to other characteristics of the invention which are intended to provide further advantages.